Going to mention Choo Choo Charles, probably the weirdest train game.

And also Voidtrain, which is about building a train as you explore endless train tracks through the void. It’s been a few months since I played but it was pretty content-light back then. Cool premise, just needs a lot of fleshing out.

What’s that other one. Unrailed! is a neat coop game where you have to mine resources to build a train track for your little always-moving train.